Nanografting of Polymer Brushes on Gold Substrate by RAFT-RIGP

Optical sensors based on surface plasmon resonance (SPR) have made great strides in the detection of various chemical and biological analytes. A is a bound, non-radiative evanescent wave generated as resonant electrons metal–dielectric to absorb energy from an incident light. As analytes bind functionalized metal substrate, refractometric response can be used for quantitation with selectivity, sensitivity, capacity label-free real-time analysis. Polymer nanobrushes are ideal recognition elements because their greater area wide range functional versatility. Here, we introduce simple “grafting-from” method covalently attach nanometer-thick polymer chains gold surface. Nanografting gold-coated BK-7 glass was performed two steps: (1) self-assembly organosulfur compounds; (2) RAFT-mediated radiation-induced graft polymerization (RAFT-RIGP) polyglycidyl methacrylate (PGMA). Surface modification monitored verified using FTIR SPR. Layer-by-layer thickness calculated Winspall 3.02 simulation fitted experimental SPR curves showed successful 1-dodecanethiol (DDT) monolayer measuring 1.4 nm. These alkane DDT served initiation sites RAFT-RIGP. controlled by adjusting absorbed dose presence chain transfer agent, 4-cyano-4-(phenylcarbonothioylthio)pentanoic acid. The molecular weight grafted polymers 2.8 4.3 kDa corresponded increase 3.6 7.9 nm, respectively. stable nanografted substrates may further sensing applications.